The principle of the interlock fitting is that the hose is skived both internally and externally in order to create two zones: one locking and one sealing. The locking is created in the front of the fitting, where nipple and ferrule are swaged together with the reinforcement of the hose. The back of the fitting is the sealing part; the sealing part is created between nipple and inner tube. The interlock fitting is recommended for hydraulic systems with very high pulsating pressure and requirements of safety.